Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto, Japan; National Research and Innovation Agency of the Republic of Indonesia, Bogor, Indonesia.
Research Institute for Sustainable Humanosphere, Kyoto University, Kyoto, Japan.
Plant Sci. 2022 Aug;321:111325. doi: 10.1016/j.plantsci.2022.111325. Epub 2022 May 16.
Sorghum has been recognized as a promising energy crop. The composition and structure of lignin in the cell wall are important factors that affect the quality of plant biomass as a bioenergy feedstock. Silicon (Si) supply may affect the lignin content and structure, as both Si and lignin are possibly involved in plant mechanical strength. However, our understanding regarding the interaction between Si and lignin in sorghum is limited. Therefore, in this study, we analyzed the lignin in the cell walls of sorghum seedlings cultured hydroponically with or without Si supplementation. Limiting the Si supply significantly increased the thioglycolic acid lignin content and thioacidolysis-derived syringyl/guaiacyl monomer ratio. At least part of the modification may be attributable to the change in gene expression, as suggested by the upregulation of phenylpropanoid biosynthesis-related genes under -Si conditions. The cell walls of the -Si plants had a higher mechanical strength and calorific value than those of the +Si plants. These results provide some insights into the enhancement of the value of sorghum biomass as a feedstock for energy production by limiting Si uptake.
高粱被认为是一种很有前途的能源作物。细胞壁中木质素的组成和结构是影响植物生物质作为生物能源原料质量的重要因素。硅（Si）供应可能会影响木质素的含量和结构，因为 Si 和木质素都可能与植物的机械强度有关。然而，我们对高粱中 Si 和木质素之间相互作用的理解是有限的。因此，在这项研究中，我们分析了水培培养的高粱幼苗细胞壁中的木质素，这些幼苗在有或没有 Si 补充的情况下进行培养。限制 Si 供应显著增加了硫代乙醇酸木质素的含量和硫代酸解衍生的愈创木基/丁香基单体的比例。至少部分修饰可能归因于基因表达的变化，因为在 -Si 条件下与苯丙烷生物合成相关的基因上调。-Si 植株的细胞壁比 +Si 植株具有更高的机械强度和热值。这些结果为通过限制 Si 吸收来提高高粱生物质作为能源生产原料的价值提供了一些见解。
